It has previously been proposed to treat oxidic or silicic acid particles with organosilicon compounds in order to modify the surface of such particles. By such modification, it is possible to influence the affinity of the treated particles in respect to the surrounding medium. The modification of the particles may be accomplished, either in physical manner by adsorption or chemically thereby that the modification agents react with the groups which are present on the surface of the particles, particularly the hydroxyl groups.
German Offenlegungsschrift No. 29 46 727 discloses a product which is used for the separation of water-oil-mixtures. This prior art product is prepared pursuant to a process wherein an inorganic solid material which contains hydroxyl groups on its surface is reacted in a first stage with a compound of the formula ##STR1##
In this formula,
R is a divalent organic group with up to 20 carbon atoms, PA1 R.sup.1 and R.sup.2 are halogen atoms or organic groups with up to 20 carbon atoms; PA1 Y is a halogen atom or a group of the formula --OR.sup.3, in which R.sup.3 is hydrogen or alkyl, aryl or acyl with up to 20 carbon atoms; and PA1 X is halogen atom. PA1 R.sup.2 is octylphenyl, nonylphenyl or dodecylphenyl, PA1 R.sup.3 and R.sup.4 are the same or different and represent lower alkyl with 1-4 carbon atoms, oxygen O.sub.0.5, hydroxy or Y, wherein Y is a hydrolyzable group, particularly --Cl, --OR.sup.5 or --NR.sub.2.sup.8, wherein PA1 R.sup.5 is alkyl with 1-4 carbon atoms and R.sup.8 is hydrogen or alkyl with 1-4 carbon atoms, PA1 n is 2 or 3 with the proviso that n=2 in at least 90 mole % of the group, and x=1-50.
The product obtained in the first stage is then reacted at elevated temperatures with an N-substituted imide of an alkenyl substituted dicarboxylic acid. The inorganic solid material used in this prior art procedure is aluminum oxide, titanium dioxide, zirconium oxide, glass, silicon dioxide, in particular silica gel as well as zeolitic molecular sieves. These solid materials, both before and after modification, are in the form of small particles of a size of 0.1 to 3.0 mm. From these treated particles, a layer in the form of a filter bed is formed through which the water-oil-mixture to be separated is passed. Upon passage through the filter layer, the mixtures are separated into their oil and water components.
German Offenlegungsschrift No. 27 43 691 discloses an aluminum hydroxide whose surface is treated with an excess amount of silane, it hydrolysate or condensate. The silane has two or three hydrolyzable groups at the silicon and an organic group with a polyoxyalkylene group. A mixture of this treated aluminum hydroxide with untreated aluminum hydroxide can be added to a plastic mass, for example, thermoplast and causes a reduction of the viscosity of the plastic mass and reduces the inflammability or burning capability of this plastic mass.
Further, German Pat. No. 27 43 682 is directed to oxidic or silicate particles which have been treated with a particular organosilane. The organosilane contains hydrolyzable groups and, within an organic group, a polyoxyalkylene chain. Such products are proposed to be used as fillers in coating masses or plastic masses, particularly in glass fiber reinforced heat hardening polyester masses.